Environmental Conflict Modulates Pavlovian Bias
Journal:
bioRxiv
Published Date:
Jan 1, 2025
Abstract
Pavlovian avoidance enables rapid defensive responding but can undermine goal-directed behaviour when it overrides instrumental control, a tendency amplified in anxiety. Whether such biases can be flexibly and rapidly modulated by environmental structure remains unknown. Here we show that global conflict in the environment can suppress Pavlovian avoidance and enhance instrumental choice, particularly in individuals high in trait anxiety. One hundred and sixteen participants completed a sequential approach–avoidance task in which three options differed in reward–punishment conflict, and blocks varied the frequency of high-conflict encounters. In low-conflict environments, participants exhibited pronounced and misplaced avoidance of objectively safe, no-conflict options indicating that choices are not determined by local contingencies alone but are tuned to broader environmental context. Interestingly, increasing environmental conflict reduced this maladaptive avoidance: approach to safe options increased, and reinforcement-learning and drift–diffusion modelling revealed higher reward sensitivity and drift rates alongside reduced lapse and Pavlovian bias parameters. These effects were strongest in high-anxious individuals, whose behaviour shifted markedly toward that of low-anxious peers. Crucially, benefits depended on the frequency of conflict encounters and were not elicited by cue–outcome reversals or increased punishment probability alone. Furthermore, a modified Go/NoGo task replicated global conflict-dependent improvements on Pavlovian-incongruent trials. Together, these results demonstrate that global environmental conflict can rapidly recalibrate the balance between Pavlovian and instrumental systems, attenuating maladaptive avoidance and disproportionately aiding anxious individuals. We propose that conflict-driven arousal dynamics, plausibly mediated by LC–NE mechanisms, promote this adaptive reconfiguration of defensive and goal-directed control. Avoiding danger is essential for survival, but sometimes our automatic fear responses make us avoid things that are actually safe and potentially rewarding. This problem is especially common in people with anxiety, where avoidance can become rigid and limit everyday functioning. In this study, we discovered that the broader structure of the environment, not just the immediate situation, can strongly influence these automatic reactions. When the environment contained more frequent conflicts or difficult choices, people actually became less avoidant, even toward options that were completely safe. Their decisions became more goal-directed, and this shift was especially strong in individuals with high anxiety, whose behaviour began to resemble that of low-anxiety individuals. These results show that anxious individuals can be more flexible and their behaviour can be rapidly improved by changing the surrounding context. This challenges assumptions about how rigid avoidance tendencies are and suggests ways to reduce maladaptive avoidance without relying solely on long or intensive training. By revealing how environmental structure can rebalance automatic fear responses and deliberate decision-making, this work opens avenues for designing interventions and potentially therapies that harness contextual factors to support more adaptive behaviour in anxiety.